This invention relates to the remote control of material handling equipment such as for handling radioactive material as radioactive waste material. More particularly, the invention relates to a method and apparatus for controlling and energizing, if desired, from a remote station, a movable carriage such as a car located in an operating space defined at least in part by a wall. Although useful for other purposes, the invention provides particular advantages in connection with the handling of radioactive materials produced or used in nuclear power generating stations, and it will be described below in connection with radioactive waste materials.
Nuclear power generating stations develop radioactive waste materials that must be disposed of, usually by placing them in containers that are removed to burial sites. These radioactive wastes usually are in the form of fluent slurries of radioactive particles in liquids but may take other forms such as radioactive cotton waste or radioactive portions of equipment.
The placing of radioactive waste material into a suitable container and handling a container having such material is a complex operation and must be accomplished in such a way that operating personnel will not be exposed to harmful radiation. Accordingly, the operation of introducing the waste material into the container must be performed in an enclosed chamber with walls that shield against passage of radioactivity harmful to human operators. It is particularly important that the operation be controlled in such a way that operators need not enter the space in which the radioactive material is placed in the container which, because of the high level of radioactivity present therein, is sometimes referred to as a "hot" area. Likewise, the external space shielded from harmful radiation and wherein operating personnel may work safely is often called a "safe" area.
Some previous techniques have utilized vehicles such as transfer cars for transporting the container between a filling station wherein radioactive material is introduced into the container, and a removal station whereat the container containing the radioactive material is removed from the car and carried away for storage. In order to operate the car, it is necessary to have equipment such as motors, electrical switches and other mechanisms within the "hot" area for energizing or control purposes. These all must have periodic maintenance that requires personnel to enter the "hot" area and thus, be exposed for periods of time to considerable radiation. This is, of course, undesirable and it is this type of operation that the present invention is intended to eliminate or greatly minimize.
The method and apparatus of the present invention reduce the types of dangers described above and afford other features and advantages heretofore not obtainable.